package win.lioil.bluetooth.util;


import java.util.List;

public class OpusUtil {
    private static final String TAG = "OpusUtil";

    private static final byte[] CAPTURE_PATTERN = new byte[]{0x4F,0x67,0x67,0x53};//页标识：ASCII字符，0x4f 'O' 0x67 'g' 0x67 'g' 0x53 'S'，4个字节大小，它标识着一个页的开始。
    private static final byte[] STREAM_STRUCTURE_VERSION = new byte[]{0x00};//版本id：一般当前版本默认为0，1个字节。

    //类型标识：标识当前的页的类型
    public static final byte[] HEADER_TYPE_FLAG_FIRST = new byte[]{0x02};//表示该页为逻辑流的第一页，bos标识
    public static final byte[] HEADER_TYPE_FLAG_END = new byte[]{0x04};//表示该页位逻辑流的最后一页，eos标识
    public static final byte[] HEADER_TYPE_FLAG_OTHER = new byte[]{0x00};//类型标识,表示该页不是逻辑流的第一页,不是最后一页,也不是延续之前packet
    public static final byte[] HEADER_TYPE_FLAG_CONTINUE = new byte[]{0x01};//本页媒体编码数据与前一页属于同一个逻辑流的同一个packet

    //granule_position共8个字节，前4字节为采样码数目的小端，后四字节填充0x00
    private static final byte[] GRANULE_POSITION_TALE = new byte[]{0x00,0x00,0x00,0x00};//媒体编码相关的参数信息，8个字节，对于音频流来说，它存储着到本页为止逻辑流在PCM输出中采样码的数目，可以由它来算得时间戳。
    private static final byte[] SERIAL_NUMBER = new byte[]{(byte) 0xA2, (byte) 0xC6,0x33,0x01};//当前页中的流的id，4个字节，它是区分本页所属逻辑流与其他逻辑流的序号，我们可以通过这个值来划分流

//    private static final byte[] PAGE_SEQUENCE_NUMBER = new byte[]{0x00,0x00,0x00,0x00};//本页在逻辑流的序号，4个字节。
    private static final byte[] CRC_PLACE_HOLDER = new byte[]{0x00,0x00,0x00,0x00};//循环冗余效验码效验，4个字节，用来效验每页的有效性。

    //每次只发送一个segment，故NUMBER_PAGE_SEGMENTS恒定为0x01，SEGMENT_TABLE恒定为一片PCM的压缩长度0x50（80）
    private static final byte[] NUMBER_PAGE_SEGMENTS = new byte[]{0x32};//给定本页在segment_table域中出现的segment个数，1个字节。
    private static final byte[] SEGMENT_TABLE = new byte[]{0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50};//表示着每个segment的长度，取值范围是0~255。由segment（1个segment就是1个字节）可以得到packet的值，每个packet的大小是以最后一个不等于255的segment结束的

    /**
     * OPUS音频流第一页page_data固定内容
     * Identification Header
     * 4f, 70, 75, 73, 48, 65, 61, 64//Magic Signature:OpusHead 8字节
     * 01//Version : 1字节 unsigned,对应值 0x01
     * 01//Output Channel Count 'C':1个字节,unsigned,声道数,它可能和编码声道数不一致,它可能被修改成packet-by-packet,对应值0x01
     * 38, 01//Pre-skip:2字节,unsigned,小端,这是要从开始播放时的解码器输出,从页面的颗粒位置减去以计算其PCM样本位置。裁剪现有Ogg的开头时Opus流是至少3840个样本（80毫秒）的预跳过时间是建议确保解码器中完全收敛。对应值0x0138=312字节
     * 80, 3e, 00, 00//Input Sample Rate:4字节,unsigned, little endian,原始输入采样,对应值0x3e80=16000
     * 00, 00//Output Gain:2字节,signed,little endian,这是解码时要应用的增益。是20 * log10缩放解码器输出以实现所需的播放音量，以16位带符号二进制存储,对应值:0x0000
     * 00//Channel Mapping Family:1字节,unsigned,该字节指示输出渠道的顺序和语音含义.该八位位组的每个当前指定的值表示一个映射系列，它定义了一组允许的通道数，以及每个允许的通道数的通道名称的有序集合.当前值0x0,表示声道数为1或者2
     * Channel Mapping Table:可选,当Channel Mapping Family为0时被省略.
     */
    private static final byte[] IDENTIFICATION_HEADER = new byte[]{0x4F,0x70,0x75,0x73,0x48,0x65,0x61,0x64,0x01,0x01,0x38,0x01, (byte) 0x80,0x3E,0x00,0x00,0x00,0x00,0x00};

    /**
     * OPUS音频流第二页page_data固定内容
     * Comment Header
     * 4f, 70, 75, 73, 54, 61, 67, 73//Magic Signature:8个字节,OpusTags
     * 27, 00, 00, 00//Vendor String Length:4个字节,unsigned,little endian:当前值:0x00000027=39字节
     * 45, 73, 70, 72, 65, 73, 73, 69, 66, 20, 53, 79, 73, 74, 65, 6d, 73, 20, 28, 53, 68, 61, 6e, 67, 68, 61, 69, 29, 20, 50, 74, 65, 2e, 2c, 20, 4c, 74, 64, 2e//Vendor String:长度由Vendor String Length指定,utf-8编码,当前值0x45 0x73 ....0x64 0x2E,内容:"Espressif Systems (Shanghai) Pte., Ltd."内容为芯片公司信息
     * 00, 00, 00, 00//User Comment List Length:4字节,unsigned, little endian,该字段指示用户提供的注释数。它可能表示用户提供的评论为零，在这种情况下数据包中没有其他字段。一定不要表示评论太多，以至于评论字符串长度将需要比其余的可用数据更多的数据数据包。当前值0x00 00 00 00 = 0个评论
     */
    private static final byte[] COMMENT_HEADER = new byte[]{0x4F,0x70,0x75,0x73,0x54,0x61,0x67,0x73,0x27,0x00,0x00,0x00,0x45,0x73,0x70,0x72,0x65,0x73,0x73,0x69,0x66,0x20,0x53,0x79,0x73,0x74,0x65,0x6D,0x73,0x20,0x28,0x53,0x68,0x61,0x6E,0x67,0x68,0x61,0x69,0x29,0x20,0x50,0x74,0x65,0x2E,0x2C,0x20,0x4C,0x74,0x64,0x2E,0x00,0x00,0x00,0x00};

    public static byte[] createFirstPage(){
        return createPageData(IDENTIFICATION_HEADER,HEADER_TYPE_FLAG_FIRST,0);
    }
    public static byte[] createSecondPage(){
        return createPageData(COMMENT_HEADER,HEADER_TYPE_FLAG_OTHER,1);
    }

    public static byte[] createPageData(List<byte[]> voiceData,byte[] headerType,int pageNum){
        byte[] pageBytes = ByteUtils.concat(CAPTURE_PATTERN,STREAM_STRUCTURE_VERSION);
        pageBytes = ByteUtils.concat(pageBytes,headerType);
//        pageBytes = ByteUtils.concat(pageBytes,GRANULE_POSITION);
//        手动计算GRANULE_POSITION
        //第一页第二页为固定内容，granulePosition为0。第三页开始每页PCM输出中的采样率为48000，页码从0开始，第三页pageNum为2，故减1
        int position = (pageNum-1)*48000;
        byte[] littlePosition = ByteUtils.little_intToByte4(position);
        byte[] granulePosition = ByteUtils.concat(littlePosition,GRANULE_POSITION_TALE);
        pageBytes = ByteUtils.concat(pageBytes,granulePosition);

        pageBytes = ByteUtils.concat(pageBytes,SERIAL_NUMBER);

//        pageBytes = ByteUtils.concat(pageBytes,PAGE_SEQUENCE_NUMBER);
        byte[] pageSequenceNumber = ByteUtils.little_intToByte4(pageNum);
        pageBytes = ByteUtils.concat(pageBytes,pageSequenceNumber);
        int crcStart = pageBytes.length;

        pageBytes = ByteUtils.concat(pageBytes,CRC_PLACE_HOLDER);

        //第一页第二页为固定内容，number_page_segments 为1,第三页开始为voiceData的长度即segment的总数
        pageBytes = ByteUtils.concat(pageBytes,new byte[]{(byte) voiceData.size()});

//        pageBytes = ByteUtils.concat(pageBytes,SEGMENT_TABLE);
//        手动计算SEGMENT_TABLE长度（原理见SEGMENT_TABLE注释）,voiceData经过处理，已经将大于长度大于255的segment分片
        byte[] segmentTable = new byte[voiceData.size()];
        for (int i = 0; i < voiceData.size(); i++){
            int segmentLength = voiceData.get(i).length;
            segmentTable[i] = (byte) segmentLength;
        }
        pageBytes = ByteUtils.concat(pageBytes,segmentTable);

        //将voiceData中的数据依次拼接
        for (int i = 0; i < voiceData.size(); i++){
            pageBytes = ByteUtils.concat(pageBytes,voiceData.get(i));
        }
        //CRC循环冗余校验码计算规则为：先用0x00,0x00,0x00,0x00占位，再从头至尾计算冗余校验码，并替换占位字节
//        CRC32 crc = new CRC32();
//        crc.update(pageBytes);
//        byte[] crc32 = ByteUtils.longToByte4(crc.getValue());
        byte[] crc32 = ByteUtils.little_intToByte4(calc32_calculate(pageBytes));
//        MyLogUtil.d(TAG,"crc32 : " + ByteUtils.toHexString(crc32));
        pageBytes[crcStart+0] = crc32[0];
        pageBytes[crcStart+1] = crc32[1];
        pageBytes[crcStart+2] = crc32[2];
        pageBytes[crcStart+3] = crc32[3];
        return pageBytes;
    }

    public static byte[] createPageData(byte[] voiceData,byte[] headerType,int pageNum){
        byte[] pageBytes = ByteUtils.concat(CAPTURE_PATTERN,STREAM_STRUCTURE_VERSION);

        pageBytes = ByteUtils.concat(pageBytes,headerType);

//        pageBytes = ByteUtils.concat(pageBytes,GRANULE_POSITION);
//        手动计算GRANULE_POSITION
        //第一页第二页为固定内容，granulePosition为0
        int position = 0;
        byte[] littlePosition = ByteUtils.little_intToByte4(position);
        byte[] granulePosition = ByteUtils.concat(littlePosition,GRANULE_POSITION_TALE);
        pageBytes = ByteUtils.concat(pageBytes,granulePosition);

        pageBytes = ByteUtils.concat(pageBytes,SERIAL_NUMBER);

//        pageBytes = ByteUtils.concat(pageBytes,PAGE_SEQUENCE_NUMBER);
        byte[] pageSequenceNumber = ByteUtils.little_intToByte4(pageNum);
        pageBytes = ByteUtils.concat(pageBytes,pageSequenceNumber);
        int crcStart = pageBytes.length;

        pageBytes = ByteUtils.concat(pageBytes,CRC_PLACE_HOLDER);

        //第一页第二页为固定内容，number_page_segments 为1
        pageBytes = ByteUtils.concat(pageBytes,new byte[]{0x01});

//        pageBytes = ByteUtils.concat(pageBytes,SEGMENT_TABLE);
//        手动计算SEGMENT_TABLE长度（原理见SEGMENT_TABLE注释）
        byte[] segmentTable = new byte[]{(byte) voiceData.length};
        pageBytes = ByteUtils.concat(pageBytes,segmentTable);
//        MyLogUtil.d(TAG,"opus page header : " + ByteUtils.toHexString(pageBytes));

        pageBytes = ByteUtils.concat(pageBytes,voiceData);

//        CRC32 crc = new CRC32();
//        crc.update(pageBytes);
//        byte[] crc32 = ByteUtils.longToByte4(crc.getValue());
        byte[] crc32 = ByteUtils.little_intToByte4(calc32_calculate(pageBytes));
//        MyLogUtil.d(TAG,"crc32 : " + ByteUtils.toHexString(crc32));
        pageBytes[crcStart+0] = crc32[0];
        pageBytes[crcStart+1] = crc32[1];
        pageBytes[crcStart+2] = crc32[2];
        pageBytes[crcStart+3] = crc32[3];
        return pageBytes;
    }

    public static byte[] createPageHeader(List<byte[]> voiceData,byte[] headerType,int pageNum){
        byte[] pageBytes = ByteUtils.concat(CAPTURE_PATTERN,STREAM_STRUCTURE_VERSION);
        pageBytes = ByteUtils.concat(pageBytes,headerType);
//        pageBytes = ByteUtils.concat(pageBytes,GRANULE_POSITION);
//        手动计算GRANULE_POSITION
        //第一页第二页为固定内容，granulePosition为0。第三页开始每页PCM输出中的采样率为48000，页码从0开始，第三页pageNum为2，故减1
        int position = (pageNum-1)*48000;
        byte[] littlePosition = ByteUtils.little_intToByte4(position);
        byte[] granulePosition = ByteUtils.concat(littlePosition,GRANULE_POSITION_TALE);
        pageBytes = ByteUtils.concat(pageBytes,granulePosition);

        pageBytes = ByteUtils.concat(pageBytes,SERIAL_NUMBER);

//        pageBytes = ByteUtils.concat(pageBytes,PAGE_SEQUENCE_NUMBER);
        byte[] pageSequenceNumber = ByteUtils.little_intToByte4(pageNum);
        pageBytes = ByteUtils.concat(pageBytes,pageSequenceNumber);

        pageBytes = ByteUtils.concat(pageBytes,CRC_PLACE_HOLDER);

        //第一页第二页为固定内容，number_page_segments 为1,第三页开始为voiceData的长度即segment的总数
        pageBytes = ByteUtils.concat(pageBytes,new byte[]{(byte) voiceData.size()});

//        pageBytes = ByteUtils.concat(pageBytes,SEGMENT_TABLE);
//        手动计算SEGMENT_TABLE长度（原理见SEGMENT_TABLE注释）,voiceData经过处理，已经将大于长度大于255的segment分片
        byte[] segmentTable = new byte[voiceData.size()];
        for (int i = 0; i < voiceData.size(); i++){
            int segmentLength = voiceData.get(i).length;
            segmentTable[i] = (byte) segmentLength;
        }
        pageBytes = ByteUtils.concat(pageBytes,segmentTable);
        return pageBytes;
    }

    public static byte[] createPageHeader(int pageNum){
        byte[] pageBytes = ByteUtils.concat(CAPTURE_PATTERN,STREAM_STRUCTURE_VERSION);

        pageBytes = ByteUtils.concat(pageBytes,HEADER_TYPE_FLAG_OTHER);

//        pageBytes = ByteUtils.concat(pageBytes,GRANULE_POSITION);
//        手动计算GRANULE_POSITION
        //第一页第二页为固定内容，granulePosition为0
        int position = 48000*(pageNum-1);
        byte[] littlePosition = ByteUtils.little_intToByte4(position);
        byte[] granulePosition = ByteUtils.concat(littlePosition,GRANULE_POSITION_TALE);
        pageBytes = ByteUtils.concat(pageBytes,granulePosition);

        pageBytes = ByteUtils.concat(pageBytes,SERIAL_NUMBER);

//        pageBytes = ByteUtils.concat(pageBytes,PAGE_SEQUENCE_NUMBER);
        byte[] pageSequenceNumber = ByteUtils.little_intToByte4(pageNum);
        pageBytes = ByteUtils.concat(pageBytes,pageSequenceNumber);

        pageBytes = ByteUtils.concat(pageBytes,CRC_PLACE_HOLDER);

        //第一页第二页为固定内容，number_page_segments 为1
        pageBytes = ByteUtils.concat(pageBytes,NUMBER_PAGE_SEGMENTS);

        pageBytes = ByteUtils.concat(pageBytes,SEGMENT_TABLE);
//        MyLogUtil.d(TAG,"opus page header : " + ByteUtils.toHexString(pageBytes));
        return pageBytes;
    }

    private static int[] crc_lookup = new int[]{
                0x00000000,0x04c11db7,0x09823b6e,0x0d4326d9,
                0x130476dc,0x17c56b6b,0x1a864db2,0x1e475005,
                0x2608edb8,0x22c9f00f,0x2f8ad6d6,0x2b4bcb61,
                0x350c9b64,0x31cd86d3,0x3c8ea00a,0x384fbdbd,
                0x4c11db70,0x48d0c6c7,0x4593e01e,0x4152fda9,
                0x5f15adac,0x5bd4b01b,0x569796c2,0x52568b75,
                0x6a1936c8,0x6ed82b7f,0x639b0da6,0x675a1011,
                0x791d4014,0x7ddc5da3,0x709f7b7a,0x745e66cd,
                0x9823b6e0,0x9ce2ab57,0x91a18d8e,0x95609039,
                0x8b27c03c,0x8fe6dd8b,0x82a5fb52,0x8664e6e5,
                0xbe2b5b58,0xbaea46ef,0xb7a96036,0xb3687d81,
                0xad2f2d84,0xa9ee3033,0xa4ad16ea,0xa06c0b5d,
                0xd4326d90,0xd0f37027,0xddb056fe,0xd9714b49,
                0xc7361b4c,0xc3f706fb,0xceb42022,0xca753d95,
                0xf23a8028,0xf6fb9d9f,0xfbb8bb46,0xff79a6f1,
                0xe13ef6f4,0xe5ffeb43,0xe8bccd9a,0xec7dd02d,
                0x34867077,0x30476dc0,0x3d044b19,0x39c556ae,
                0x278206ab,0x23431b1c,0x2e003dc5,0x2ac12072,
                0x128e9dcf,0x164f8078,0x1b0ca6a1,0x1fcdbb16,
                0x018aeb13,0x054bf6a4,0x0808d07d,0x0cc9cdca,
                0x7897ab07,0x7c56b6b0,0x71159069,0x75d48dde,
                0x6b93dddb,0x6f52c06c,0x6211e6b5,0x66d0fb02,
                0x5e9f46bf,0x5a5e5b08,0x571d7dd1,0x53dc6066,
                0x4d9b3063,0x495a2dd4,0x44190b0d,0x40d816ba,
                0xaca5c697,0xa864db20,0xa527fdf9,0xa1e6e04e,
                0xbfa1b04b,0xbb60adfc,0xb6238b25,0xb2e29692,
                0x8aad2b2f,0x8e6c3698,0x832f1041,0x87ee0df6,
                0x99a95df3,0x9d684044,0x902b669d,0x94ea7b2a,
                0xe0b41de7,0xe4750050,0xe9362689,0xedf73b3e,
                0xf3b06b3b,0xf771768c,0xfa325055,0xfef34de2,
                0xc6bcf05f,0xc27dede8,0xcf3ecb31,0xcbffd686,
                0xd5b88683,0xd1799b34,0xdc3abded,0xd8fba05a,
                0x690ce0ee,0x6dcdfd59,0x608edb80,0x644fc637,
                0x7a089632,0x7ec98b85,0x738aad5c,0x774bb0eb,
                0x4f040d56,0x4bc510e1,0x46863638,0x42472b8f,
                0x5c007b8a,0x58c1663d,0x558240e4,0x51435d53,
                0x251d3b9e,0x21dc2629,0x2c9f00f0,0x285e1d47,
                0x36194d42,0x32d850f5,0x3f9b762c,0x3b5a6b9b,
                0x0315d626,0x07d4cb91,0x0a97ed48,0x0e56f0ff,
                0x1011a0fa,0x14d0bd4d,0x19939b94,0x1d528623,
                0xf12f560e,0xf5ee4bb9,0xf8ad6d60,0xfc6c70d7,
                0xe22b20d2,0xe6ea3d65,0xeba91bbc,0xef68060b,
                0xd727bbb6,0xd3e6a601,0xdea580d8,0xda649d6f,
                0xc423cd6a,0xc0e2d0dd,0xcda1f604,0xc960ebb3,
                0xbd3e8d7e,0xb9ff90c9,0xb4bcb610,0xb07daba7,
                0xae3afba2,0xaafbe615,0xa7b8c0cc,0xa379dd7b,
                0x9b3660c6,0x9ff77d71,0x92b45ba8,0x9675461f,
                0x8832161a,0x8cf30bad,0x81b02d74,0x857130c3,
                0x5d8a9099,0x594b8d2e,0x5408abf7,0x50c9b640,
                0x4e8ee645,0x4a4ffbf2,0x470cdd2b,0x43cdc09c,
                0x7b827d21,0x7f436096,0x7200464f,0x76c15bf8,
                0x68860bfd,0x6c47164a,0x61043093,0x65c52d24,
                0x119b4be9,0x155a565e,0x18197087,0x1cd86d30,
                0x029f3d35,0x065e2082,0x0b1d065b,0x0fdc1bec,
                0x3793a651,0x3352bbe6,0x3e119d3f,0x3ad08088,
                0x2497d08d,0x2056cd3a,0x2d15ebe3,0x29d4f654,
                0xc5a92679,0xc1683bce,0xcc2b1d17,0xc8ea00a0,
                0xd6ad50a5,0xd26c4d12,0xdf2f6bcb,0xdbee767c,
                0xe3a1cbc1,0xe760d676,0xea23f0af,0xeee2ed18,
                0xf0a5bd1d,0xf464a0aa,0xf9278673,0xfde69bc4,
                0x89b8fd09,0x8d79e0be,0x803ac667,0x84fbdbd0,
                0x9abc8bd5,0x9e7d9662,0x933eb0bb,0x97ffad0c,
                0xafb010b1,0xab710d06,0xa6322bdf,0xa2f33668,
                0xbcb4666d,0xb8757bda,0xb5365d03,0xb1f740b4};


    public static int getCRC32(byte[] bytes){
        int crc = 0xffffffff;
        for (byte b : bytes){
            crc = (crc >>> 8 ^ crc_lookup[(crc ^ b) & 0xff]);
        }
        crc = crc ^ 0xffffffff;
        return crc;
    }

    public static int getUint16(int i){
        return i & 0x0000ffff;
    }
    public static int CALC_CRC32(int x, byte y)
    {
        //return (ushort)(((x >> 8) & 0xff) ^ wCRC16Table[((x & 0xff) ^ (y & 0xff))]);
        int index = ((x >> 24) & 0xff);
        short Y = y;
//        MyLogUtil.d(TAG,"get uint index: " + index);
        return (x << 8) ^ crc_lookup[(index ^ Y) & 0x00ff];
    }

    public static int calc32_calculate(byte[] dataStream)
    {

        int i;
        int checksum = 0;
        for (i = 0; i < dataStream.length; i++)
        {
            checksum = CALC_CRC32(checksum, dataStream[i]);
        }
        return checksum;
    }
}
